Watch crown

ABSTRACT

A WATCH CROWN FOR A WATERPROOF WATCH INCLUDES A METAL OR PLASTIC CROWN BODY HAVING AN INTERIOR CAVITY. A TUBULAR PENDANT PROTRUBING FROM THE BEZEL PORTION OF THE CASE OF THE WATCH IS ADAPTED TO FIT WITHIN THE CAVITY OF THE CROWN BODY. WATERPROOF SEALING IS OBTAINED BY THE USE OF A MOLDED ELASTIC GASKET WHICH IS HELD IN PLACE IN THE CROWN BY A RING WHICH IS FIXED TO THE CROWN BODY. THE GASKET, IN CROSS-SECTION, HAS A FLAT WASHER-LIKE PORTION AND, INTEGRAL THERETO AT THE INNER DIAMETER OF THE WASHER, A RAISED FLANGE-LIKE PORTION HAVING AN ARCUATE INNER FACE.

United States Patent fice 3,618,312 Patented Nov. 9, 1971 3,618,312WATCH CROWN William W. Macchia, Naugatuck, and Cyril F. Seymour,Middlebury, Conn., assignors to Timex Corporation Filed Apr. 29, 1969,Ser. No. 820,190 Int. Cl. G04b 37/08 US. C]. 58-90 B 3 Claims ABSTRACTOF THE DISCLOSURE A watch crown for a waterproof watch includes a metalor plastic crown body having an interior cavity. A tubular pendantprotruding from the bezel portion of the case of the watch is adapted tofit within the cavity of the crown body. Waterproof sealing is obtainedby the use of a molded elastic gasket which is held in place in thecrown by a ring which is fixed to the crown body. The gasket, incross-section, has a fiat washer-like portion and, integral thereto atthe inner diameter of the washer, a raised flange-like portion having anarcuate inner face.

DESCRIPTION The present invention relates to horology and moreparticularly to a crown for a waterproof watch.

It has generally been though desirable that a watch should bewaterproof. Watches, even when treated with care, occasionally maybecome wet, for example, due to rain or accidental immersion. Whenwatches were a luxury item, they Were treated with considerable care.Wrist watches were removed from the wrist before washing the hands.However, wrist watches are no longer considered a luxury item and theyare often treated carelesslythey are left on when washing the hands,when going out in the rain, or even when swimming or bathing. 'Peoplenevertheless expect that their watches will continue to operate, despitethe adverse treatment to which they subject them. There is a demand thateven relatively lowpriced watches be waterproofed.

The demand for low-priced waterproof watches has presented difiicultiesto watch manufacturers. Some of the devices which provide waterproofnessin a watch are too expensive to be utilized in low-priced watches. Onthe other hand, there have been proposed various waterproofing methodswhich, although low in cost, are impractical or only operate for a shorttime and thereafter cease to protect the watch,

The problem of waterproofing inexpensive watches has been particularlyacute in obtaining a satisfactory waterproof watch crown. The watchcrown is used in a mechanical watch to wind the mainspring and to setthe hands. In winding the mainspring the watch crown is connected to awinding staff, which is co-axially within a tubular pendant fixed to thebezel of the watch and the winding staff is turned upon rotation of thecrown. The crown is pulled outward away from the body of the watch androtated in order to set the hands.

The watch crown sealing element must perform various functions. It mustkeep the watch waterproof during the normal position of the crown, thatis, with the crown pressed inwardly against the watch body. It must alsoprevent leakage of water into the pendant when the crown is pulledoutward in order to set the hands. In addition, the waterproofingmechanism must permit the crown to rotate in relationship to thependant, both in its winding and hand-setting positions. It is importantthat the rotation of the crown not cause the waterproofing seal tobecome worn out; for, if that seal should fail, Water may flow fromoutside of the crown, through the pendant and into the watch, harming ordestroying its mechanism.

It is the objective of the present invention to provide a crown for awatch, which crown provides a waterproof seal, is relativelyinexpensive, and may be assembled with a minimum of labor.

It is a further objective of the present invention to provide such acrown which does not readily wear out with use, which provides awaterproof seal setween the crown and the pendant, and yet permitsrotation of the crown.

In accordance with the present invention a watch crown is provided. Thecrown includes a plastic or metal crown body, preferably havingconventional outer teeth. The crown body has an inner cavity. Apedestal, integral with the body, is positioned at the top of the cavityand protrudes into the cavity. The pedestal has a bore for aninterference fit, or other attachment means, so that it may be fastened,either permanently or removably, to the winding stem of the watch. Thecavity is adapted to fit over the tubular case pendant, which protrudesfrom the bezel of the watch. An annular elastic gasket is held withinthe cavity by a metal or plastic ring, the ring being staked, glued orotherwise joined to the crown body. In cross-section, the gasket has abottom flat washer-like portion and a raised flange-like portion at theinner diameter of the washer-like portion. The flat washer-like portionof the gasket is firmly positioned between the top surface of the ringand the bottom of a ledge formed in the crown body. The flange-likeportion, on its inner surface, is curved but on its outer surface isflat. The outer surface of the flange-like portion is held against acircumferential wall of the cavity of the crown body. The curved innersurface of the flange portion of the gasket, when the crown body is inits position on the pendant of the watch, is compressed against thependant. The gasket is firmly held within the crown body even when thecrown body is removed from the watch. It will not fall out of the crownbody and may be exactly centered within the cavity of the crown body.The curved surface of the gasket permits rotation of the crown bodywithout binding. At the same time the gasket provides an excellent sealagainst water.

Other objectives of the present invention will be apparent from thefollowing detailed description of a preferred embodiment taken inconjunction with the accompanying drawings, in which:

FIG. 1 is a side cross-sectional view of the watch crown of the presentinvention in its position on the watch;

FIG. 2 is a side view, the left half in section and the right half inplan, showing the crown removed from the watch;

FIG. 3 is a sectional view of the gasket ring; and

FIG. 4 is a bottom plan View of the watch crown of the presentinvention.

As shown in FIGS. 1 and 2, the watch crown of the present inventionincludes a crown body 1, preferably made from metal or plastic. The body1 has an exterior set of conventional external teeth (knurlings) 2 andare used to grip the crown. A cavity 3 is formed within the body 1. Thebody has a hollow pedestal portion 4 which protrudes into the cavity 3.The pedestal portion 4 has a bore 5 which is adapted to grip theexternal teeth 6 of the winding stem 7. Alternatively, the bore ofpedestal 4 may have internal screw threads adapted to be screwed to theexterior screw threads of the winding stem. The setting stem 7 is around staff which is rotatable within the tubular pendant 8. The tubularpendant 8 is integral with, and protrudes from, the bezel or otherportion of the watch case. A ring 10, in the form of a metal or plasticwasher (a fiat annular shape) is attached to the crown body 1. Theattachment may be, as shown, by staking a lip 11 of the crown body overthe ring 10 or alternatively by adhesive or other joining means. Theflat outer diameter wall of the ring may be close to, or rest against,the internal wall portion 12 of the crown. The gasket 13 is in the formof a ring. Preferably the gasket is made of a moldable elastic material,for example, the plastic resin polyurethane. The gasket includes abottom washer-like portion 14 and an upright flange portion 15. Thebottom portion .14, which is in the form of a fiat washer, is heldbetween the upper (internal) face of the ring 10 and the downwardlyinclined ledge 17 of the crown body. The flange-like portion 15 of thegasket has, at its inner diameter, a curved arcuate face 16. The curvedface 16 presents the same type of low resistance surface to the pendant8 as would be presented by an O ring. However, the gasket 13 presentsthe advantage, as compared to an O ring, of being firmly held in placewithin the crown body. Due to its being compressed between the ledge 17and the upper surface of the ring 10, the gasket prevents water leakagebetween the ring and the crown.

We claim:

1. A waterproof watch crown comprising a crown body having an intervalcavity, said crown body being adapted to fit over a watch case tubularpendant, said crown body having a tubular portion within said cavityextending outwardly from the top of the cavity in the crown body to fitwithin the said case pendant and to be attached to the winding stem of awatch; an annular molded elastic gasket within said cavity adapted to becompressed between said crown and said pendant to form a seal; and anannular hard washer having an inner round hole fitted about the pendantand being fixedly attached at the bottom thereof to a 'lower portion ofsaid crown to partly cover said cavity and retain said gasket withinsaid cavity, said engagement of the pendant with the inner round holepreventing adverse effects on the seal from side loading of the crown;wherein said gasket viewed in cross-section has as integral portions abottom flat Washer-like portion and a flange-like upper portion at theinner edge of said fiat portion, said flange-like portion having anarcuate inner face and a fiat outer face; and wherein said washerlikeportion is clamped tightly between said hard washer and said crown bodyto form a seal.

2. A watch crown as in claim 1 wherein the internal wall of said cavityin said crown body forms a first enlarged cylindrical cavity portionand, above said first portion, a second smaller cylindrical cavityportion, the walls forming between them a ledge, said gasket, at itswasher-like portion, being clamped between said ledge and the top ofsaid hard washer to form a seal.

3. A watch crown as in claim 1 wherein the hard washer is of metal andstaked in place within the crown.

References Cited UNITED STATES PATENTS 2,771,734 11/1956 Morf 58-90 B2,784,547 3/1957 Waldman 5890 B 3,475,901 11/1969 Soguel 58--90 BFOREIGN PATENTS 1,204,013 1/ 1960 France 58-90 B 1,216,990 4/1960 France5890 B 272,324 12/1950 Switzerland 5890 B RICHARD B. WILKINSON, PrimaryExaminer G. H. MILLER, JR., Assistant Examiner

